Upper Limits on the VHE Gamma-Ray Emission from the Willman 1 Satellite Galaxy with the Magic Telescope

We present the result of the observation of the ultrafaint dwarf galaxy Willman 1 performed with the 17 m MAGIC telescope during 15.5 hr between March and May 2008. No significant γ-ray emission was found. We derived upper limits of the order of 10-12 ph cm-2 s-1 on the integral flux above 100 GeV,...

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Detalles Bibliográficos
Autores: Paredes i Poy, Josep Maria, Ribó Gomis, Marc, Bosch i Ramon, Valentí, Moldón Vara, Francisco Javier, Zabalza de Torres, Víctor, Bordas Coma, Pol, MAGIC Collaboration
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2009
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/150834
Acceso en línea:https://hdl.handle.net/2445/150834
Access Level:acceso abierto
Palabra clave:Matèria fosca (Astronomia)
Raigs gamma
Galàxies
Dark matter (Astronomy)
Gamma rays
Galaxies
Descripción
Sumario:We present the result of the observation of the ultrafaint dwarf galaxy Willman 1 performed with the 17 m MAGIC telescope during 15.5 hr between March and May 2008. No significant γ-ray emission was found. We derived upper limits of the order of 10-12 ph cm-2 s-1 on the integral flux above 100 GeV, which we compare with predictions from several of the established neutralino benchmark models in the mSUGRA parameter space. The neutralino annihilation spectra are defined after including the recently quantified contribution of internal bremsstrahlung from the virtual sparticles that mediate the annihilation. Flux boost factors of three orders of magnitude are required even in the most optimistic scenario to match our upper limits. However, uncertainties in the dark matter intrinsic and extrinsic properties (e.g., presence of substructures, Sommerfeld effect) may significantly reduce this gap.